Space weather experts believe people will soon wear devices warning of impending strikes from solar storms.

The Sun's 11-year cycle of activity reaches its violent climax this year and US officials are "anticipating a higher frequency of more severe storms this year".

The comment was made at the annual meeting of the American Association for the Advancement of Science in Washington DC.

"Everyone will have their own wireless wrist display to get forecasts of space weather," predicted Gary Heckman from US National Oceanic and Atmospheric Administration (NOAA).

These would warn people of likely power blackouts, so they could shut down any critical systems.

Cancer induction

The devices are already being developed by Nasa, to be worn by astronauts during spacewalks. They are not primarily concerned about the geomagnetic effects of space storms, but the increased radiation flux which could send the astronauts' cancer risks soaring.

Solar activity goes in 11-year cycles

Mark Weyland, Lockheed Martin's space radiation group, said: "We need to keep radiation doses to the crew as low as possible. It is very topical as we have a shuttle in orbit now and there has been high solar activity.

"We are worried about cancer induction - it won't happen right away, but this is the one risk of space flight that doesn't go away when you land."

If a storm is predicted when the astronauts are inside the shuttle, they would take shelter in the airlock, the most protected place. If they are outside, they may be able to shelter in the lee of the orbiter.

The habitation module for the International Space Station (ISS) is being designed with extra shielding, though the rest of the ISS is not.